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<title>Debugging with GDB: Tracepoint Variables</title>

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<a name="Tracepoint-Variables"></a>
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<p>
Next: <a href="Trace-Files.html#Trace-Files" accesskey="n" rel="next">Trace Files</a>, Previous: <a href="Analyze-Collected-Data.html#Analyze-Collected-Data" accesskey="p" rel="prev">Analyze Collected Data</a>, Up: <a href="Tracepoints.html#Tracepoints" accesskey="u" rel="up">Tracepoints</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
<a name="Convenience-Variables-for-Tracepoints"></a>
<h3 class="section">13.3 Convenience Variables for Tracepoints</h3>
<a name="index-tracepoint-variables"></a>
<a name="index-convenience-variables-for-tracepoints"></a>

<dl compact="compact">
<dd><a name="index-_0024trace_005fframe"></a>
</dd>
<dt><code>(int) $trace_frame</code></dt>
<dd><p>The current trace snapshot (a.k.a. <em>frame</em>) number, or -1 if no
snapshot is selected.
</p>
<a name="index-_0024tracepoint"></a>
</dd>
<dt><code>(int) $tracepoint</code></dt>
<dd><p>The tracepoint for the current trace snapshot.
</p>
<a name="index-_0024trace_005fline"></a>
</dd>
<dt><code>(int) $trace_line</code></dt>
<dd><p>The line number for the current trace snapshot.
</p>
<a name="index-_0024trace_005ffile"></a>
</dd>
<dt><code>(char []) $trace_file</code></dt>
<dd><p>The source file for the current trace snapshot.
</p>
<a name="index-_0024trace_005ffunc"></a>
</dd>
<dt><code>(char []) $trace_func</code></dt>
<dd><p>The name of the function containing <code>$tracepoint</code>.
</p></dd>
</dl>

<p>Note: <code>$trace_file</code> is not suitable for use in <code>printf</code>,
use <code>output</code> instead.
</p>
<p>Here&rsquo;s a simple example of using these convenience variables for
stepping through all the trace snapshots and printing some of their
data.  Note that these are not the same as trace state variables,
which are managed by the target.
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) <b>tfind start</b>

(gdb) <b>while $trace_frame != -1</b>
&gt; output $trace_file
&gt; printf &quot;, line %d (tracepoint #%d)\n&quot;, $trace_line, $tracepoint
&gt; tfind
&gt; end
</pre></div>




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